1. Field of the Invention
This invention relates to the preparation of 2-(phenyl)amino-3-carboxy-9(10H)acridinone (ACA) and its conversion to 2-(phenyl)amino-9(10H)acridinone, also named 2-anilinoacridone (AA), by decarboxylation in tetramethylene sulfone (TMS) in the presence of basic copper carbonate catalyst. ACA is prepared by half-cyclization of 2,5-di(phenylamino)terephthalic acid (DAA) in a mixture of polyphosphoric acid (PPA) and phosphoric acid (H.sub.3 PO.sub.4) at moderate temperature and short reaction time.
2. Prior Art
Quinacridonequinone has the requisites of a high-quality golden-yellow pigment except satisfactory lightfastness. This has been remedied by forming solid solutions with other components acting as stabilizers. U.S. Pat. No. 3,160,510 discloses solid solutions with quinacridone derivatives; they are limited in use by having an overall reddish color. U.S. Pat. Nos. 3,341,345 and 3,748,162 disclose colorless quinacridonequinone stabilizers such as N,N'-diphenyl-p-phenylenediamine and 6,13-dihydroquinacridone which, however, also affect the color of the final pigment composition more than is desirable.
U.S. Pat. No. 4,286,998 discloses AA and related compounds as stabilizers for quinacridonequinone pigment having minimal effect on the original quinacridonequinone color.
The compound AA was made by L. Kalb [Berichte 43, 2212 (1910)] by condensing N-phenyl-p-phenylenediamine with 2-chlorobenzoic acid in amyl alcohol and in the presence of copper powder and copper (I) chloride as catalysts to form 4'-(phenyl)amino-2-carboxydiphenylamine and cyclizing to form 2-(phenyl) amino-9(10H)acridinone. The first reaction step produces dark blue oxidation by-products which are difficult to remove from the yellow product.
British Pat. No. 1,382,259 discloses the preparation of 2(N-aryl)amino-3-carboxy-9(10H) acridinone from 2-(N-aryl)amino-3-alkoxy-carbonyl-1,4-dihydro-9(10H)acridinone which can be prepared by half-cyclizing 1,4-dialkoxy-carbonyl-2,5-di(N-aryl)amino-1,4-cyclohexadiene, as British Pat. No. 1,368,970 discloses.
U.S. Pat. No. 4,258,190 discloses the preparation of 1,2,3,4-tetrahydro-7-(phenyl)amino-9(10H)-acridinone and its dehydrogenation in the presence of supported palladium or platinum catalyst to form AA. The 1,2,3,4-tetrahydro-7-(phenyl)-amino-9(10H)acridinone can be prepared from either a 2-cyclohexanonecarboxylate ester or from the reaction product of cyclohexanone and an oxalate ester in the presence of an alkoxide base, hydrolyzed and decarbonylated to form a 2-cyclohexanonecarboxylate ester by reacting said carboxylate ester with N-phenyl-p-phenylenediamine in the presence of a catalyst to form a phenylaminocyclohexenecarboxylate ester and cyclizing to form 1,2,3,4-tetrahydro-7-(phenyl) amino-9(10H)acridinone.